Consider a right-angled triangle with an inside angle of 30° and a hypotenuse of 8cm. Calculate the length of the opposite side to the 30° angle.
Recall the trigonometry rule SOH/CAH/TOA (Silly Old Hitler Couldn't Advance His Troops Over Africa).
- Label: Draw the triangle and label the sides with Hyp, Opp & Adj.
- Choose: Pick which equation to use from SOH/CAH/TOA. In this case, we choose "SOH" because we want to find the opposite side
and we are given the angle and the length of the hypotenuse. - Cover: Using the triangle form of the equation for SOH, cover up what you want to find and write down the expression of what
you see. So opp = sin(angle) x hyp - Substitute: opp = sin(angle) x hyp then becomes opp = sin(30) x 8
- Evaluate: opp = 0.5 x 8 = 4cm
JL
Related Maths GCSE answers
All answers ▸How to do Indices?
There are a total of 50 apples and pears (apples + pears) in a large basket. If the total number of apples was doubled and the total number of pears was tripled, these two numbers would add up to 130. How many apples and pears are in the basket?
You are given a triangle ABC with sides length AB = 20cm, BC = 100cm and angle A = 70 degrees. Find the angle of C in degrees.
How do you solve an algebraic equation?